y axis issues

Let me start by saying that the Y axis belt seems tight enough.
When starting up it often will not travel all the way to activate the limit switch.
It is a physical binding. You can't force it further.
Tearing the bed off and reassembling will solve it for a number of prints.
However it gets back to the same situation. Then homing it will cause it to try and go to the limit
It just can't...

Not sure what is the best thing to look at. Once you get it fixed it works fine for a day or two.

 

Not sure what is causing the binding. Y axis belt too loose? Too tight?
I lubricated the slider bears last time, they are moving smoothly.

 

Found it and documented it:
http://forums.robo3dprinter.com/index.php?threads/y-axis-blues.1221/#post-7828

Wierd issue. I do not think it can re-occur since that drive sprocket is now loctite reinforced.

 

I guess this is moot at this point.